Error 'xcodebuild: Returned an unsuccessful exit code' after trying publishing Pod

The problem comes down to this line in your podspec:

s.source = { :git => 'https://github.com/Ar7Style/GTNetworkQualityChecker.git', :tag => s.version.to_s }

The :tag is the problem. Your current pod validation doesn't know which commit represents the definitive end of what you want to release, which would be your "0.1.0" version. That's why the validation step is referring to an older version of your repo (where you did have FrameworkStoryboard.storyboard existing before you deleted it).

In other words, you need to tag your Pod with a tag that corresponds to your version number.

For example, at the command line:

git tag '0.1.0' # the version number you're using for this release
git push --tags

Then do the validation step that I showed you up above:

pod spec lint --verbose GTNetworkQualityChecker.podspec

And if it passes, then you should do your pod trunk push --verbose.